(1) Field of the Invention
The present invention relates to a conduit for use in a weld wire dispensing system or as a control cable conduit. In particular, the present invention relates to a conduit constructed of coiled wire having an oval or elliptical cross-section.
(2) Description of Related Art
In the past, spring liners for weld torch cables, and weld wire conduits, used in weld wire dispensing systems have been constructed using wire having a rectangular cross-section. However, in instances where the weld torch cable or weld wire conduit is bent or flexed, the edges of the wire forming the conduit are exposed. The exposed edges of the wire forming the conduit damage the surface of the weld wire as the weld wire is pushed or pulled through the conduit in the weld torch cable or weld wire conduit. The sharp edges of the wire “shave” or cut the weld wire as the weld wire is moved through the conduit. The sharp edges also increase the coefficient of friction between the weld wire and the conduit as the weld wire is moved through the weld torch cable or weld wire conduit. The higher coefficient of friction results in more force being required to move the weld wire through the conduit which decreases the overall efficiency of the weld wire dispensing system. The damage to the surface of the weld wire by the exposed edges of the wire forming the conduit also results in shavings and residue collecting in the inner passageway of the conduit. In some instances, the build-up of shavings and residue eventually prevents the weld wire from being pulled or pushed through the conduit. In addition, as the shavings and residue build-up in the conduit, the shavings and residue significantly increase the coefficient of friction between the weld wire and the conduit and thus increase the amount of force needed to push or pull the weld wire through the conduit. The increase in friction also causes drive roll wire slippage in the weld wire dispensing system, as well as burn-back in the system. The shavings and residue can also lead to the weld wire being stuck inside the torch contact tip.
In the past, the conduits have also been constructed of wire having a circular cross-section. However, it is difficult to provide a protective coating on only the inner surface of the conduit constructed of round wire. Round wire tends to rotate in dies; therefore, it is extremely difficult to get one (1) side of the round wire in a continuous position as necessary to provide coating on only the inner surface of the conduit.
There remains a need for a conduit to be used as a spring liner or as a control cable conduit which is constructed of wire having an oval or elliptical cross-sectional shape.